package com.hbnu.test.www;

import java.util.Scanner;

public class CompareLetter1 {
    public static void main(String[] args) {
        char letter;
        Scanner scan = new Scanner(System.in);
        letter = scan.next().charAt(0);//scan.next()为获取单行,加charAt(0)代表获取该行首字符
        if(letter == 'A'){
            System.out.print("优秀");
        }
        else if(letter == 'B'){
            System.out.print("良好");
        }
        else if(letter == 'C'){
            System.out.print("及格");
        }
        else if(letter == 'D'){
            System.out.print("不及格");
        }
        else{
            System.out.print("未知等级");
        }
    }
}